PAYMENT_REQUIRED

The resource needs payment; the response describes how.

HTTP status	402
Group	x402
Retryable	No — sending it again changes nothing

What happened

This is the x402 challenge, not a failure: the body lists what is accepted and at what price.

What to do

Pay against one of the accepts entries and repeat the request with the payment header.

The problem document

Every error is application/problem+json (RFC 9457) with the same shape:

{
  "type": "https://docs.co-relayer.com/errors/payment-required",
  "title": "The resource needs payment; the response describes how.",
  "status": 402,
  "detail": "A sentence about this specific occurrence.",
  "instance": "req_01JB…",
  "code": "PAYMENT_REQUIRED",
  "retryable": false,
  "hint": "Pay against one of the `accepts` entries and repeat the request with the payment header."
}

See the error model for what each member means and how to handle unknown codes.